If they show up and cancel on you, they get penalized in the app. UberXL is a big vehicle, if you are just moving suitcases/bags should be no problem.

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Not saying they won't do it, but drivers who wait until they see the passenger to cancel can have various negative affects. If they have more than 5% cancel rate, they lose the ability to see upcoming trip durations before accepting a ride. They can lose other perks, and theoretically they can be completely deactivated but I suspect that's rare.